Analysis of the Occurrence of Extreme Rainfall and Hydrological Events in the Cavally River watershed (Western Cote d'Ivoire)

In Côte d'Ivoire, the lack of knowledge of flows at the outlet of basins and the frequency of floods sometimes lead to poor sizing of hydraulic structures. The Cavally River watershed has suffered in recent years from recurrent flooding phenomena that cause significant damage to the population. The objective of this study is to analyse the occurrence of extreme rainfall and hydrological events that may occur in the Cavally River watershed located in western Côte d'Ivoire. To achieve this objective, daily data from three (03) hydrometric stations located on the Cavally River and three (03) rainfall stations were used. To do this, three (3) statistical methods of frequency analysis (Gumbel, Fréchet and Weibull) were adopted. These analyses show that the statistical law that best fits the series of maximum flows and maximum rains is the Weibull law. Project rains of 2; 5; 10; 10; 20; 50 and 100 years are 91.2; 133; 160; 187; 221; 246 mm respectively. The project flows are 246; 293; 316; 334; 353 and 365 m/s respectively for the return periods of 2; 5; 10; 20; 50 and 100 years. These results could guide decision-making on the design of hydraulic structures in the western region of Côte d'Ivoire.